Compass accuracy

Even though one cannot expect great accuracy from the magnetic sensor in the watch, I recently noticed that my Instinct may be off by almost 20 degrees, which seems excessive. The best way to see the problem without requiring a proper compass as reference is to first point the watch at a given bearing/azimuth and then point it in the opposite direction. The readings should, of course, differ by 180 degrees. In my case, when using an Easy/West axis I get a difference of 145/150 degrees (e.g., 270 and 055), even though in the North/South axis the difference is, indeed, close to 180, as expected (e.g., 0 and 178). To avoid any potential errors introduced by the local declination compensation, I always did this using the magnetic north (and after proper calibration, of course). Are errors of this magnitude the norm with your Instincts, or is it just me? Thank you in advance.

  • The Instinct series has been out for over 2 years at this point and there has not been a pattern of reports with compass issues. At this point, there is a large number of them out there and the series has many different models due to their overall success. Researching across the different variations, I see no patterns of a compass issue.

    The concern for your compass issue would be that your specific Instinct watch has a bad compass. If you haven't already, please calibrate your compass to see if it resolves your variance issue. It is considerably off and should not be.

    This Support Center article taken from the manual goes over calibrating the compass:

    - www8.garmin.com/.../GUID-4C4297B5-1632-4CC8-98B9-67C6682A3745.html

    If you continue to have an issue, you can soft reset your Instinct by holding down your top left power button until it shuts off, then let go of the button. If still no luck, you can fully reset it within the System > Reset menu.

    Please reach out to your regional Outdoor Product Support if your compass issue does not resolve.

  • Thank you, Chris, for the prompt reply. I will hang on to my Instinct, though. This behavior is not a deal breaker, and this has been a good, reliable unit. All I have to do is to use a -17.5sin(360-Z) correction term, and I can pretty much approximate it in my head, which makes my watch even better: it now has an anti-Alzheimer feature. :)

  • I have tried your test and I see difference 10 degrees. Which is I would say usual azimuth error for the Instinct. I tested the "Sight ’N Go" function, but it is quite useless, because azimuth is set only at the beginning and the result is very unreliable.

     What is the result of the correction term?

  • I totally agree with you that a 10 degree difference between an azimuth and it's opposite is not too bad. Your watch seems to be fine. Thank you for having taken the time to do the test.

    In my case, the difference can be of up to 35 degrees, when those azimuths lie near the East/West axis (e.g. 285/072). The watch is biased, somehow always closer to North than it should. That is why I always try to shift my compass readings towards southern azimuths with that correction term (mentally approximated). That is:when my watch reads 288, I know that the true magnetic azimuth is approximately 270, when it says 090, the true magnetic azimuth is probably 105. North, however, is always North, and South is always South. It works.for me, but it is a concocted scheme I came up with for the particular case of my semi-broken magnetic compass. Nothing that you should also use, even because your watch seems to behave acceptably in this regard.

    Enjoy your watch and its healthy compass (which I envy a lot :) )

  • Did you check it in test mode? (Switch the watch on while the "ABC" key is pressed for about 20 sec).

    The compass needs working 3D accelerometer and 3D magnetometer.

  • Great idea. Did not think of it. In fact, test mode shows that  both sensors are working in all three dimensions, but it may allow me to try to determine which direction is misbehaving (if that is the case). Thank you.

  • I am not completely sure what your issue is, but if you want the compass to point to magnetic north, change its settings. By default it points to the "true" north, so this is why it may look wrong.

    I have nothing to compare the readings, but I have used it to find my way back home and it definitely helps, even though it may be wrong by several degrees.

    Sorry, if I misunderstood what you said and if I am making noise.

  • In fact, the issue has nothing to do with magnetic north versus true north. Either way, an azimuth and its reverse should always differ by 180 degrees. But when you try to help someone, the qualifier "noise" is never applicable. It is always kindness, never noise. :)

    Thank you, sspanak